ICT Materials Research Group

Daejeon, South Korea

ICT Materials Research Group

Daejeon, South Korea
SEARCH FILTERS
Time filter
Source Type

Lee J.,ICT Materials Research Group | Choi N.-J.,ICT Materials Research Group | Lee H.-K.,ICT Materials Research Group | Kim J.,ICT Materials Research Group | And 6 more authors.
Sensors and Actuators, B: Chemical | Year: 2017

Micro carbon dioxide gas sensor with low power consumption and high selectivity was fabricated based on micro-heater and electrochemical operation method. Li3PO4 thick film for solid electrolyte and Li2CO3 thick film for sensing material were deposited successively using screen printing technique on Si substrate in the form of slurry. In structure of micro-heater, the resistances of the two semi-circled Pt heaters are connected to the spreader for thermal uniformity. Based on the above design, a low power consumption carbon dioxide gas sensor was fabricated using a CMOS compatible MEMS process. Bridge type micro-heater based on Si substrate was fabricated by surface micromachining technique. Micro gas sensor showed a value of about 50.5 mV/decade for air based carbon dioxide gas with 59 mW power consumption. © 2017 Elsevier B.V.


Lee J.,ICT Materials Research Group | Kim J.,ICT Materials Research Group | Lim S.-Y.,ICT Materials Research Group | Kwon J.-Y.,ICT Materials Research Group | And 3 more authors.
Electronics Letters | Year: 2017

An electrical resistivity evaluation method for a pillar-shaped solid material, especially a brittle thermoelectric Bi2Te3, is presented with short compensation based on a probing apparatus with four-spring pins. The method eliminates the process of modelling a complex contact resistance, resulting in a simple but reproducible characterisation without any contamination on the surface in comparison to either a conventional paste or welding contact. Furthermore, it enables a small electrical or thermoelectric material <2 mm thick to be appropriately evaluated, which can erect and align a pillar-shaped material with electrical terminals, in spite of a small surface area. To extract the resistivity of a Bi2Te3 pillar with the volume of 2 × 2 × 1.6 mm, Alumina 6061-T6 material identical with that of Bi2Te3 was used as a reference material for the short compensation. Thus, the modelled resistance and its resistivity were 2.46 ± 0.11 mΩ and 6.15 ± 0.28 Ω-μm, respectively, in the range of 2-10 kHz, demonstrating the validity of the method. © The Institution of Engineering and Technology 2017.

Loading ICT Materials Research Group collaborators
Loading ICT Materials Research Group collaborators